1mko: Difference between revisions
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[[Image:1mko.jpg|left|200px]] | [[Image:1mko.jpg|left|200px]] | ||
'''A Fourth Quaternary Structure of Human Hemoglobin A at 2.18 A Resolution''' | {{Structure | ||
|PDB= 1mko |SIZE=350|CAPTION= <scene name='initialview01'>1mko</scene>, resolution 2.18Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=CMO:CARBON+MONOXIDE'>CMO</scene> and <scene name='pdbligand=HEM:PROTOPORPHYRIN IX CONTAINING FE'>HEM</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''A Fourth Quaternary Structure of Human Hemoglobin A at 2.18 A Resolution''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1MKO is a [ | 1MKO is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MKO OCA]. | ||
==Reference== | ==Reference== | ||
The enigma of the liganded hemoglobin end state: a novel quaternary structure of human carbonmonoxy hemoglobin., Safo MK, Abraham DJ, Biochemistry. 2005 Jun 14;44(23):8347-59. PMID:[http:// | The enigma of the liganded hemoglobin end state: a novel quaternary structure of human carbonmonoxy hemoglobin., Safo MK, Abraham DJ, Biochemistry. 2005 Jun 14;44(23):8347-59. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15938624 15938624] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: rr2 state]] | [[Category: rr2 state]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:44:38 2008'' | ||
Revision as of 10:44, 20 March 2008
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| 1mko, resolution 2.18Å | |||||||||||||
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| Ligands: | PO4, CMO and HEM | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
A Fourth Quaternary Structure of Human Hemoglobin A at 2.18 A Resolution
Overview
The liganded hemoglobin (Hb) high-salt crystallization condition described by Max Perutz has generated three different crystals of human adult carbonmonoxy hemoglobin (COHbA). The first crystal is isomorphous with the "classical" liganded or R Hb structure. The second crystal reveals a new liganded Hb quaternary structure, RR2, that assumes an intermediate conformation between the R form and another liganded Hb quaternary structure, R2, which was discovered more than a decade ago. Like the R2 structure, the diagnostic R state hydrogen bond between beta2His97 and alpha1Thr38 is missing in the RR2 structure. The third crystal adopts a novel liganded Hb conformation, which we have termed R3, and it shows substantial quaternary structural differences from the R, RR2, and R2 structures. The quaternary structure differences between T and R3 are as large as those between T and R2; however, the T --> R3 and T --> R2 transitions are in different directions as defined by rigid-body screw rotation. Moreover, R3 represents an end state. Compared to all known liganded Hb structures, R3 shows remarkably reduced strain at the alpha-heme, reduced steric contact between the beta-heme ligand and the distal residues, smaller alpha- and beta-clefts, and reduced alpha1-alpha2 and beta1-beta2 iron-iron distances. Together, these unique structural features in R3 should make it the most relaxed and/or greatly enhance its affinity for oxygen compared to the other liganded Hbs. The current Hb structure-function relationships that are now based on T --> R, T -->R --> R2, or T --> R2 --> R transitions may have to be reexamined to take into account the RR2 and R3 liganded structures.
Disease
Known diseases associated with this structure: Erythremias, alpha- OMIM:[141800], Erythremias, beta- OMIM:[141900], Erythrocytosis OMIM:[141850], HPFH, deletion type OMIM:[141900], Heinz body anemia OMIM:[141850], Heinz body anemias, alpha- OMIM:[141800], Heinz body anemias, beta- OMIM:[141900], Hemoglobin H disease OMIM:[141850], Hypochromic microcytic anemia OMIM:[141850], Methemoglobinemias, alpha- OMIM:[141800], Methemoglobinemias, beta- OMIM:[141900], Sickle cell anemia OMIM:[141900], Thalassemia, alpha- OMIM:[141850], Thalassemia-beta, dominant inclusion-body OMIM:[141900], Thalassemias, alpha- OMIM:[141800], Thalassemias, beta- OMIM:[141900]
About this Structure
1MKO is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The enigma of the liganded hemoglobin end state: a novel quaternary structure of human carbonmonoxy hemoglobin., Safo MK, Abraham DJ, Biochemistry. 2005 Jun 14;44(23):8347-59. PMID:15938624
Page seeded by OCA on Thu Mar 20 12:44:38 2008
